Distributed Energy Resources
Future Market Options
ERCOT Staff
DER Workshop
June 18, 2015
1
DER Concept Paper
•
ERCOT Staff is committed to publishing a concept paper on Distributed
Energy Resources (DERs) by third quarter of 2015
– Draft is under development
– Preliminary outline was released to ETWG in April and is posted to today’s
meeting page
•
•
Today’s workshop is part of an ongoing effort by ERCOT to engage
with Market Participants and solicit input
Concept paper will include:
– Potential market options for DERs
– Data Requirements
• DER mapping to ERCOT CIM from TDSPs
• Real-time or near-Real Time Resource-specific (single site or
aggregations) operational data from QSEs
– Registration / Interconnection Requirements
• ERCOT
• TDSP
– Metering issues
– Settlement Mechanisms
– Forecasting tools
– Compliance metrics
DER Workshop June 18, 2015
2
Defining DER
• ERCOT definition of Distributed Generation (DG):
– An electrical generating facility located at a Customer’s point of delivery
(point of common coupling) ten megawatts (MW) or less and connected
at a voltage less than or equal to 60 kilovolts (kV) which may be
connected in parallel operation to the utility system.
• ERCOT definition of Distributed Renewable Generation (DRG)
– Electric generation with a capacity of not more than 2,000 kW provided
by a renewable energy technology that is installed on a retail electric
Customer’s side of the meter.
• DER (currently undefined in ERCOT) may include:
– Technologies such as solar photovoltaic (PV), combined heat and power
(CHP) or cogeneration systems, microgrids, wind turbines, microturbines,
back-up generators, energy storage or any combination of such.
– Demand Response?
DER Workshop June 18, 2015
3
Examples of DER definitions
• EPRI:
– ….smaller power sources that can be aggregated to provide power
necessary to meet regular demand.
• New York ISO (from DNV GL report):
– ….behind-the-meter” power generation and storage resources typically
located on an end-use customer’s premises and operated for the
purpose of supplying all or a portion of the customer’s electric load.
• NREL:
– ….as used in this report, refers to a variety of small, modular electricitygenerating or storage technologies that are located close to the load
they serve.
DER Workshop June 18, 2015
4
Current ERCOT DG Rules
• Registration with ERCOT
– DG greater than the 1 MW DG registration requirement
• Registration with ERCOT is required
• The resource production will be accounted for in wholesale
generation settlements
– DG equal to or below the 1 MW DG registration threshold
• Registration with ERCOT is permitted, but not required
• Unregistered DG outflow is accounted for in the load
aggregation process for settlements
DER Workshop June 18, 2015
5
DG Metering - Data Collection & Data Submittal
• Registered DG
– Resource Entity and TDSP agree on metering
• ERCOT Polled Settlement (EPS) Meter
– EPS Meter data will be included in initial settlements
• TDSP-Read Generation Meter
– TDSP-Read meter data will be included in settlement when
data is received from the TDSP
» Typically submitted on a monthly basis
» 867 Transaction (IDR Meter)
DER Workshop June 18, 2015
6
DG Metering - Data Collection & Data Submittal
• Unregistered DG
– In NOIE Territories
• Unregistered DG outflows are not submitted to ERCOT
– In Competitive areas
• Unregistered DG outflows are submitted to ERCOT by the TDSP
through the Texas SET retail transaction process
– ESI ID must be assigned a DG load profile type
– AMS interval data (LSE File) or
– NIDR 867 transaction
DER Workshop June 18, 2015
7
DG Settlement
• Registered DG Settlement
– Compensated at the Load Zone Settlement Point Price (LZ SPP)
• LZ SPP is a Load-weighted average of all Locational Marginal
Prices (LMPs) in a Load Zone for a given 15-minute Settlement
Interval.
• Unregistered DG Settlement
– NOIE Territories
• Unregistered DG outflows are accounted for by a load reduction at
the NOIE boundary metering points
– Competitive areas
• Outflows are treated as negative load in the ERCOT data
aggregation process (effectively compensated at LZ SPP)
• The load of the Competitive Retailer associated with the ESI ID is
reduced by the amount of the outflow energy
DER Workshop June 18, 2015
8
Metering Types
Type
Notes
Unidirectional
Measures consumption only
Load only (no DG)
‘Traditional’
Net metering
Single-channel non-directional.
Single data point representing net
Load minus net on-site generation
over a billing period (could be a
negative number).
Mostly disallowed by PUC
Rule 25.213.
Bi-directional
Two data points for each 15-minute
interval: measures net in-flow to the
point of delivery (i.e., may be
reduced by on-site DG), and net
exports to the grid from the point of
delivery.
Required by PUC Rule for
investor-owned TDSPs
Dual metering
Two meters, two data points for each
15-minute interval: measures gross
Load and gross generation.
Allows DSP to bill customer
based on gross
consumption; allows LSE to
pay customer for gross
generation.
DER Workshop June 18, 2015
9
DERs on the horizon
• More PV is coming – we just don’t know how much or how fast
• 30% federal solar investment tax credit:
– Residential credit expires completely 12/31/16
– Commercial credit reduces to 10% after 12/31/16
• But PV prices keep plummeting….
eere.doe.gov
• Meanwhile, efficiency keeps improving and costs are coming
down for:
– Firm backup/emergency DG
– Distribution-level storage devices
DER Workshop June 18, 2015
10
DER Energy Pricing
• DERs today are settled on the applicable LZ SPP if the energy
meter records a net injection into the grid (at meter location)
• Applies to both:
– Injections to the grid by registered DG with QSE representation
– Negative load treatment for an unregistered DG’s Load Serving Entity
• In other words, DERs today are ‘passive’ participants to prices:
– Controlled passive response – e.g. fossil fuel, PV + storage, or storage –
may chase LZ SPPs
– Uncontrolled passive response – e.g., pure PV – they produce when the
sun is shining
DER Workshop June 18, 2015
11
Optional LMPs for DERs
•
If DERs were eligible to be settled on more granular pricing, then
passive response could better align with grid conditions
– Higher local prices indicate local scarcity – signaling DERs to chase these prices
if they are capable of doing so
•
DERs would need to be mapped to appropriate electrical bus(es), and
settled at that electrical bus (or average of multiple buses) price
•
Proposed to be optional: Entity representing the DER could choose
whether to get LZ SPP pricing or the locational price
•
If it’s the locational price, then the DER should meet further
requirements:
– Telemetry or some other type of real-time or near-real-time communication to the
ISO (active power, status, etc.)
– Revenue quality metering (AMI/IDR/EPS) that measures DER gross output
separate from the gross load behind common service delivery point
– This is necessary to ensure compliance with PUC Rules 25.501 which requires
all load in the ERCOT region to be settled at the applicable Load Zone Price
DER Workshop June 18, 2015
12
DER Market Options
Type
Energy Settled at:
Energy Market
Participation
Ancillary Service Market
Participation
Aggregation Allowed?
DER Minimal
DER Light
DER Heavy
Load Zone SPP
Logical Resource Node
Price at Local electrical
(price at Local electrical
bus(es)
bus(es))
Self-responding
Self-responding
SCED-dispatched
Not eligible
Not eligible
Eligible
N/A
Yes
Yes
Single meter OK (15- Separate (dual)
minute revenue quality) metering for Generation
at POI
and native Load
Real-time or near realNot required
time with multiple
attributes
Separate (dual) metering
for Generation and native
Load
Real-time or near realtime with multiple
attributes
COP, Outage Schedule,
Offers/Bids, etc.
N/A
N/A
Required
CRR Implications
None
None
None/?
Metering Required
Telemetry or telemetrylight to and from ERCOT
DER Workshop June 18, 2015
13
Ancillary Services from DERs
• DER participation in the AS markets would require new sets of
market rules
–
–
–
–
Registration
Qualification
Validation
Aggregation issues – i.e., similar challenges to enabling Aggregated
Load Resources (for Load Participation in SCED)
• Expected growth of dispatchable DERs featuring integrated PV
+ storage creates challenges AND opportunities
DER Workshop June 18, 2015
14
DER interconnections
• Regions that have experienced high DER penetration have
found it necessary to adopt a common set of interconnection
requirements
– Germany, Hawaii, and California have either adopted or are in the process of
adopting common set of requirements for distributed PV (smart inverter).
– As an example, the requirements for a DER installation could include:
a. Two-way communication/control between DER and remote entity
b. Anti-Islanding Protection
c. Low and High Voltage Ride-Through
d. Low and High Frequency Ride-Through
e. Dynamic Volt-Var Operation
f. Ramp Rates
g. Fixed Power Factor
h. Soft Start Reconnection
• Should there be a common set of DER interconnection
requirements in the ERCOT Region?
DER Workshop June 18, 2015
15
DER Operational Issues
• ERCOT Demand/Load Forecasting
– What should ERCOT be forecasting?
• Net load forecast only -- i.e., net load forecast would incorporate
DER impacts
• Net load forecast and DER forecast separately -- provide
information on both for planners, developers, grid operators and
markets
• Impact of storage on forecasting both net load and DER – this is a
challenge that needs to be addressed if there is significant adoption
of this technology
– Currently ERCOT has a project to forecast Solar PV for utility scale
(transmission connected) installations, but not distributed solar
DER Workshop June 18, 2015
16
DER Operational Issues
• Should ERCOT’s Capacity, Demand & Reserve reports account
for DERs and also include forecasted DER growth?
– CDR provides important information on expected reserves, reserve
margins, and is closely monitored by market participants
• How should ERCOT take into account impact of DER on
Operations planning (Outage coordination, Resource
availability planning, etc.) ?
– Should transmission outage approval process include potential impact
of expected DERs? Is net load forecast sufficient?
– What other operational procedures need to include potential impact of
expected DERs?
• Reliability Unit Commitment (RUC) process?
• Others?
DER Workshop June 18, 2015
17
Next Steps
• ERCOT recommends that stakeholders provide written
comments on today’s presentation and discussion
– Please provide by Friday, July 10 to paul.wattles@ercot.com and
sainath.moorty@ercot.com
• ERCOT will ask TAC for guidance on the appropriate forum for
future DER discussions
• Concept paper to be posted in September
DER Workshop June 18, 2015
18
Questions?
DER Workshop June 18, 2015
19
APPENDIX
DER Workshop June 18, 2015
20
Topics
• Nomenclature
• DG Registration Requirements
• Metering, Data Collection and Data Submittal
• DG Settlements
• Unregistered DG Report
• Interconnection Issues
• Impacts on ISO Operations
DER Workshop June 18, 2015
21
Nomenclature
ERCOT Protocol Terms
• Customer
An Entity that purchases electricity for its consumption.
• Service Delivery Point
The specific point on the system where electricity flows from the TSP or
DSP to a Customer.
• Electric Service Identifier (ESI ID)
The basic identifier assigned to each Service Delivery Point used in the
registration and settlement systems managed by ERCOT or another
Independent Organization.
• Premise
A Service Delivery Point or combination of Service Delivery Points that is
assigned a single ESI ID for Settlement and registration.
DER Workshop June 18, 2015
22
Nomenclature
ERCOT Protocol Terms (continued)
• Distributed Generation (DG)
An electrical generating facility located at a Customer’s point of delivery
(point of common coupling) ten megawatts (MW) or less and connected at
a voltage less than or equal to 60 kilovolts (kV) which may be connected in
parallel operation to the utility system.
• Distributed Renewable Generation (DRG)
Electric generation with a capacity of not more than 2,000 kW provided by a
renewable energy technology that is installed on a retail electric Customer’s
side of the meter.
• Telemetry for typical ISO requirements
Real-Time information of active, reactive power, voltage, current, frequency,
switch status, etc. Typically data refreshed in a 2 second cycle
DER Workshop June 18, 2015
23
Unregistered DG Report
2015 1st Quarter Un-Registered DG Report - LZ Summary
Aggregate
MW
kWh exported to the grid
during the prior 12
months
LZ_AEN
4.64
1,109,442
LZ_CPS
LZ_HOUSTON
0.226
1.15289
13,889
594,966
LZ_NORTH
6.855145
1,806,961
LZ_SOUTH
3.22531
889,070
LZ_WEST
0.94248
554,103
Load Zone
NOTE1: Current DG registration threshold = 1MW
NOTE2: Report includes un-registered DG above 50kW and equal to or below
________the DG threshold
NOTE3: Installed capacity limit per load zone = 10 MW
DER Workshop June 18, 2015
24